Does a player perform better in the majors if they spend some time at each minor level, or at least like .5 years at each level?

Also, does a player perform worse as a rookie in the majors than 6 years later, give the same ability level?

As far as we can tell, and confirmed by developers many years ago, only ratings affect quality of play. Nothing hidden. So no to both of your questions.

MiLB service time and age have no affect on major league performance. Players will play to their ratings regardless if they are 18 or 35.

Okay, do players ratings develop better if they go through the minors normally, or is it just playing time itself? Thanks!

It's all about playing time, the quality of their coaches, and the amount of money you have in training. Of course, injuries do also affect things, and that's where the amount of money you have in medical makes a difference.

To elaborate on what bjshumacher said, the higher levels have the best coaches, so in theory with all else being equal, players would develop best in the majors.

Thank you all!

From the Player's Guide: Player development is of the utmost importance in HBD. It is impacted by a multitude of factors: the player's makeup rating, the quality of the coaching staff, playing time, injuries, age appropriateness for level of play and potential demotion setbacks.

"age appropriateness for level of play"

Over the years, HBD management has made contradicting statements on this.

They've said the better the coaches at the players level, the better they'll develop.

They've said players should be at their appropriate MinL level and promoted very season.

They've said keeping a player at the same MinL hurts their development.

Playing time seems to matter a lot. What position they pay at does not seem to matter.

You'll need to run years and years of test to determine if it's better to start your #1 draft picks at Rookie or LowA and move them up each season, or put them where your best MinL coaches are (probably AAA) and keep them there 3-5 seasons.